Fix invalid __virt_clone generation for abstract classes (#1013)

compiler/data/class-data.cpp

@@ -114,7 +114,7 @@ FunctionPtr ClassData::add_virt_clone() {
   std::string virt_clone_f_name = replace_backslashes(name) + "$$" + NAME_OF_VIRT_CLONE;
 
   auto param_list = VertexAdaptor<op_func_param_list>::create(gen_param_this({}));
-  auto body = !modifiers.is_abstract()
+  auto body = !is_interface()
               ? VertexAdaptor<op_seq>::create(VertexAdaptor<op_return>::create(clone_this))
               : VertexAdaptor<op_seq>::create();
   auto v_op_function = VertexAdaptor<op_function>::create(param_list, body);

tests/phpt/clone_keyword/010_clone_abstract.php

@@ -0,0 +1,99 @@
+@ok
+<?php
+
+abstract class Base {
+}
+
+class PurchaseAdd {
+  public ?Reward1 $bonus_reward1 = null;
+  public ?Reward2 $bonus_reward2 = null;
+
+  function __construct(?Reward1 $bonus_reward1, ?Reward2 $bonus_reward2) {
+    $this->bonus_reward1 = $bonus_reward1;
+    $this->bonus_reward2 = $bonus_reward2;
+  }
+
+  public function __clone() {
+    if ($this->bonus_reward1 !== null) {
+      $this->bonus_reward1 = clone $this->bonus_reward1;
+    }
+    if ($this->bonus_reward2 !== null) {
+      $this->bonus_reward2 = clone $this->bonus_reward2;
+    }
+  }
+}
+
+abstract class Reward1 {
+  abstract function out();
+}
+
+interface Reward2 {
+  function out();
+}
+
+final class PackReward1 extends Reward1 {
+  public ?int $pack = null;
+
+  function __construct(?int $pack) { $this->pack = $pack; }
+  function out() { echo $this->pack, "\n"; }
+}
+
+final class PackReward2 implements Reward2 {
+  public ?int $pack = null;
+
+  function __construct(?int $pack) { $this->pack = $pack; }
+  function out() { echo $this->pack, "\n"; }
+}
+
+final class DiscountReward1 extends Reward1 {
+  public ?string $discount = null;
+
+  function __construct(?string $discount) { $this->discount = $discount; }
+  function out() { echo $this->discount, "!\n"; }
+}
+
+final class DiscountReward2 implements Reward2 {
+  public ?string $discount = null;
+
+  function __construct(?string $discount) { $this->discount = $discount; }
+  function out() { echo $this->discount, "!\n"; }
+}
+
+function test1() {
+    $add = clone (new PurchaseAdd(null, null));
+    var_dump($add->bonus_reward1 === null);
+    var_dump($add->bonus_reward2 === null);
+}
+
+function test2() {
+    $orig1 = new PackReward1(10);
+    $orig2 = new PackReward2(10);
+    $add = clone (new PurchaseAdd($orig1, $orig2));
+    $orig1->pack = 20;
+    $orig2->pack = 20;
+    $orig1->out();
+    $orig2->out();
+    $add->bonus_reward1->out();
+    $add->bonus_reward2->out();
+}
+
+function test3() {
+    $add = clone (new PurchaseAdd(new DiscountReward1('asdf'), new DiscountReward2('asdf')));
+    $add->bonus_reward1->out();
+    $add->bonus_reward2->out();
+}
+
+function clTest(Reward1 $r) {
+    $r2 = clone $r;
+    if ($r instanceof PackReward1) {
+        $r->pack = 20;
+    }
+    $r2->out();
+    $r->out();
+}
+
+test1();
+test2();
+test3();
+
+clTest(new PackReward1(10));